ATLANTA -- Between 13 and 128 Americans have been infected with the AIDS virus by their dentists or surgeons over the 10-year course of the epidemic so far, the federal Centers for Disease Control has concluded in a statistical estimate.

The estimate is based on statistical formulas comparing the estimated number of dentists and surgeons infected with the human immunodeficiency virus (HIV), the number of invasive procedures they perform and the theoretical risk of transmitting the virus during them.

The CDC estimated that 1,248 dentists are infected with HIV and have passed the virus to between 10 and 100 patients during tooth extractions, oral surgery or other invasive procedures during the past 10 years. Similarly, the agency estimates 336 HIV-infected surgeons have transmitted infections to between three and 28 patients.

CDC researchers reported last month that a Florida dentist with AIDS who has since died, David Acer, infected three of his patients.

The CDC concluded that the risk of an HIV-infected surgeon transmitting the infection to a single patient during surgery ranges from 1 in 41,667 to 1 in 416,667. The best estimate of the risk to a dental patient during a procedure where bleeding is likely ranges from 1 in 263,158 to 1 in 2,631,579.

The American Medical Association and the American Dental Association each said last month their HIV-infected members should either warn their patients about their conditions or give up performing surgery.

The issue has arisen in Baltimore, where Johns Hopkins Hospital surgeon Rudolph Almaraz, who has since died, reportedly operated on about 1,800 patients after becoming infected with HIV.